Cerebrovascular CO2 reactivity in migraine with aura and without aura. A transcranial Doppler study

Introduction - We studied by means of Transcranial Doppler (TCD) recordings the CO2 cerebrovascular reactivity in migraine patients during the headache-free period. Material and methods - In three groups of subjects (15 controls, 15 suffering from migraine with aura and 15 from migraine without aura) the middle cerebral artery (MCA) mean flow velocity (MFV) was recorded under basal condition and hypocapnia induced by hyperventilation. Relative MFV, PI (Pulsatility Index) changes and Reactivity Index (RI) were calculated. Results - Reactivity Index values were: 0.019 ± 0.007 (mean ± SD) in control subjects: 0.029 ± 0.008 in migraine with aura; 0.022 ± 0.008 in migraine without aura. Statistical analysis showed a significantly (P<0.05) increased RI in migraine with aura group. Conclusion - Cerebrovascular CO2 reactivity is increased during the interictal period in migraine with aura patients.